python - 浏览器中的图像缓存 - app-engine-patch 应用程序

Question

我在为我的应用引擎应用程序在浏览器中缓存图像时遇到了一点问题我发送最后修改、过期和缓存控制 header ，但图像每次都是从服务器加载的。这是代码的标题部分:

response['Content-Type'] = '图片/jpg'

response['Last-Modified'] = current_time.strftime('%a, %d %b %Y %H:%M:%S GMT')

response['Expires'] = current_time + timedelta(days=30)

response['Cache-Control'] = 'public, max-age=2592000'

Answer 1

这是我在 dpaste 中修复副本的示例代码 here

def view_image(request, key):
  data = memcache.get(key)  
  if data is not None:  
    if(request.META.get('HTTP_IF_MODIFIED_SINCE') >= data['Last-Modified']):  
      data.status_code = 304  
    return data  
  else:  
    image_content_blob = #some code to get the image from the data store  
    current_time = datetime.utcnow()
    response = HttpResponse()
    last_modified = current_time - timedelta(days=1)
    response['Content-Type'] = 'image/jpg'
    response['Last-Modified'] = last_modified.strftime('%a, %d %b %Y %H:%M:%S GMT')
    response['Expires'] = current_time + timedelta(days=30)
    response['Cache-Control']  = 'public, max-age=315360000'
    response['Date']           = current_time
    response.content = image_content_blob

    memcache.add(image_key, response, 86400)
    return response